In a long term evolution-advanced (hereinafter referred to as LTE) mobile communication system, a CA method of adding a component carrier (CC) is used for increasing a data rate of the LTE mobile communication system without affecting a user equipment (UE) using a single carrier. Particularly, the CA method is applied to the LTE mobile communication system from a release 10 version.
The CA method may be categorized into an intra-band CA method, where CCs exist in the same frequency band according to carrier frequency allocation of each of the CCs, and an inter-band CA method where CCs exist in another frequency band.
Moreover, the intra-band CA method may be categorized into a contiguous CA method, where CCs exist in a just adjacent frequency band according to a frequency offset between CCs, and a non-contiguous (or non-adjacent) CA method where CCs exist in a non-adjacent frequency band.
Since network providers are mostly allocated CCs by a unit of 5 MHz to 10 MHz in the same frequency band due to fairness of frequency use, an intra-band non-contiguous CA method or an inter-band CA method is generally implemented rather than an intra-band contiguous CA method.
Recently, new standard is applied to an 802.11af system using a TV white space frequency band. Here, the TV white space frequency band denotes an empty frequency band which is not used by broadcast providers in a very high frequency (VHF) band and an ultra-high frequency (UHF) band which are distributed as bands for TV broadcast. The TV white space frequency band spatially denotes a frequency band which is emptied for avoiding frequency interference between broadcast providers or a frequency band which is not used by districts, and temporally denotes a broadcast frequency which is emptied at a time when a broadcast provider does not transmit broadcast.
Since the TV white space frequency band uses a wideband frequency spectrum of 54 MHz to 698 MHz and an available channel frequency is frequently changed by districts or every use time, it is required to develop a transmitter which are configured with a wideband amplifier and a wideband antenna.
Even in a case of the 802.11af system using the TV white space frequency band, in order to support a non-adjacent CA or a non-contiguous CA, signals of difference channels may be coupled to each other, and a driver amplifier having wideband characteristic is needed. However, a transmitter including a driver amplifier is not developed to date.